SO what could be bad about a Mediterranean cruise with boss Oprah Winfrey picking up the tab?

How about an unexpected tax bill from Uncle Sam.

Oprah staffers treated to a 10-day luxury cruise through Spain, Italy, Turkey, Greece and Malta will probably have to cough up taxes to the government.

While an Oprah spokesman says that’s not the case — “The cruise is a gift from Ms. Winfrey to her staff for their sacrifices . . . ” he told The Post — Pace University Professor of Law Bridget Crawford strongly disagrees.

“I have significant doubts about that,” she says. “You cannot make a ‘gift’ in an income tax sense without ‘love in the heart’ — and you can’t have love in the heart for people you don’t know.

“If I were the IRS, and that’s the tax position [Oprah] took, she’d be audit No. 1.”

Winfrey, 55, reportedly shelled out $9.2 million for the cruise, which began last weekend and reportedly covers 1,700 guests at approximately $5,400 a pop aboard the Norwegian Gem.

“You’re looking at over $1,000 per person in taxes,” says Crawford, who teaches federal income tax law. “If you’re an employee of Oprah’s, you’re very unhappy right now.”

Crawford says that you’re allowed to make a non-taxable “gift” valued at $13,000 — again with the “love in the heart” stipulation.

“But when transferred from employer to employee the presumption is that it’s not a gift,” she says.

“[The cruise] could be a requirement of the job, but that’s probably not going to fly. [The staffers] have a big tax bill coming to them.”

If that’s the case, it won’t be the first time that Oprah’s good intentions have gone somewhat awry. On the 2004 season premiere of “Oprah,” she gave 276 audience members brand-new Pontiac G6 sedans, donated by GM and worth about $28,000 apiece.

But Pontiac only covered the sales tax on the cars — meaning everyone had to pay state and federal taxes estimated at roughly $6,000. Several of the sedans were eventually sold by people who couldn’t afford them.